I bet this is the same thing as this bug: [IGN-8411] Curly brackets (braces) on commented line in udt instance script causes script to fail silently
which is basically that curly brackets are mishandled in these scripts... and the tag team has been too afraid of breaking things to tackle this.
edit: yep, not just comments: [IGN-8411] Curly brackets (braces) on commented line in udt instance script causes script to fail silently - #11 by tyler.bennett